The present invention relates to a low-profile antenna for use in mobile computing devices, and more particularly, to an antenna having a meandering configuration.
Various configurations have been proposed for antennas used in mobile computing devices.
FIG. 1 shows a portion of a Personal Computer Memory Card International Association (PCMCIA) card having a wireless modem. U.S. Pat. No. 5,373,149, assigned to AT&T Bell Laboratories, shows circuit card 76 having located thereon battery 80, antenna 82, infra-red transceiver 84, transmit/receive electronics 86 and electrical contacts 92. Antenna 82 depends on circuit card 76 to radiate. Since the personal computer used with the wireless modem also naturally radiates energy, the personal computer and the wireless modem interfere with each other.
FIG. 2 shows an end of a PCMCIA wireless modem package opposite the end inserted into a PCMCIA slot of a computing device. U.S. Pat. No. 5,583,521, assigned to GEC Plessey Semiconductors, Inc., shows PCMCIA package 3 with transparent containment 5 (suggested in phantom) that contains a low profile, paired L-shape antenna system including vertical legs 6a′, 6b′ and horizontal legs 6a″, 6b″ made of copper wire and separated in a diversity pattern. Horizontal legs 6a″, 6b″ meander in a horizontal plane within transparent containment 5. The antenna system avoids use of a conventional monopole whip antenna that cannot readily fit into a low profile enclosure. Shielded package 3 acts as a ground plane system for the antenna system.
FIG. 3 shows an extendable whip antenna for use in a mobile telephone having a radiating element with a meandering and cylindrical configuration. U.S. Pat. No. 6,351,241, assigned to Allgon AB, shows elongated dielectric portion 30 having a length essentially equal to the length of cylindrically configured meander element 35. Impedance matching means 32 connects to a feed point of meander element 35, is integrated on dielectric carrier 33, and includes contacts at its base for connection to signal and ground connectors of the telephone. As compared to a helical antenna, the meander antenna provides a greater bandwidth, improved production tolerances leading to less rejections, a lower degree of coupling to any adjacent radiators greatly improving multi-band operability and integration of a matching network using at least partly the same manufacturing technique. Unfortunately, as mentioned, the whip antenna cannot fit into a low-profile package.
Since the wireless modem, as well as the personal computer used with the wireless modem, naturally radiates energy, the personal computer and the wireless modem interfere with each other. Accordingly, it is desirable to provide a wireless modem in a low-profile package that is more immune to interference from the computing device with which the wireless modem is used.